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[Units] Heterogeneous unit for pressure per time
by Dina Goldshtein 28 Feb '15

28 Feb '15

Hi, I asked about this in StackOverflow<http://stackoverflow.com/questions/27519186/boost-heterogeneous-unit-bar-pe…> but didn't get any answers so I thought I'd try here as well. I need to create a unit which represents pressure per time, specifically Bar per Minute. I tried creating it in the same way as I created similar units before: typedef boost::units::derived_dimension<boost::units::length_base_dimension, -1, boost::units::mass_base_dimension, 1, boost::units::time_base_dimension, -3>::type pressure_roc_dimension; typedef boost::units::unit<pressure_roc_dimension, boost::units::make_system<boost::units::metric::bar_base_unit, boost::units::metric::minute_base_unit>::type> bar_per_minute_unit; BOOST_UNITS_STATIC_CONSTANT(BarPerMinute, bar_per_minute_unit::unit_type); typedef boost::units::quantity<bar_per_minute_unit, double> BarPerMinuteRoC; And then I try to use it: BarPerMinuteRoC bpm = 5.0 * BarPerMinute; But this line doesn't compile with quite a long error trail which I'm having a bit of trouble understanding fully. 1>c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(197): error C2039: 'item' : is not a member of 'boost::units::dimensionless_type' 1> c:\workspace\externals\boost_1_57_0\include\boost\units\dimensionless_type.hpp(37) : see declaration of 'boost::units::dimensionless_type' 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(259) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations_skip_zeros_impl<true,false>::apply<RowsBegin,1,1,3,Result>' being compiled 1> with 1> [ 1> RowsBegin=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>,boost::units::detail::determine_extra_equations_skip_zeros_impl<false,true>::apply<boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>,1,0,3,boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>>>::next_equations> 1> , Result=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(264) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations<2,false>::apply<boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>,boost::units::detail::determine_extra_equations_skip_zeros_impl<false,true>::apply<boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>,1,0,3,Result>::next_equations>,3,Result>' being compiled 1> with 1> [ 1> Result=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(538) : see reference to class template instantiation 'boost::units::detail::determine_extra_equations<3,false>::apply<Matrix,3,Matrix>' being compiled 1> with 1> [ 1> Matrix=boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(828) : see reference to class template instantiation 'boost::units::detail::make_square_and_invert<boost::units::list<boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<0,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::detail::make_zero_vector<0>::type>>>,boost::units::list<boost::units::list<boost::units::static_rational<-1,1>,boost::units::list<boost::units::static_rational<1,1>,boost::units::list<boost::units::static_rational<-2,1>,boost::units::detail::expand_dimensions<0>::apply<boost::units::dimensionless_type,boost::units::dimensionless_type>::type>>>,boost::units::dimensionless_type>>>' being compiled 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(1032) : see reference to class template instantiation 'boost::units::detail::normalize_units<T>' being compiled 1> with 1> [ 1> T=boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\detail\linear_algebra.hpp(1051) : see reference to class template instantiation 'boost::units::detail::calculate_base_unit_exponents_impl<false>::apply<T,Dimensions>' being compiled 1> with 1> [ 1> T=boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>> 1> , Dimensions=BSII::Units::pressure_roc_dimension 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\heterogeneous_system.hpp(243) : see reference to class template instantiation 'boost::units::detail::calculate_base_unit_exponents<boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<T,boost::units::dimensionless_type>>,Dimensions>' being compiled 1> with 1> [ 1> T=boost::units::metric::bar_base_unit 1> , Dimensions=BSII::Units::pressure_roc_dimension 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\unit.hpp(92) : see reference to class template instantiation 'boost::units::detail::make_heterogeneous_system<Dim,System>' being compiled 1> with 1> [ 1> Dim=BSII::Units::pressure_roc_dimension 1> , System=boost::units::homogeneous_system<boost::units::list<boost::units::scaled_base_unit<boost::units::si::second_base_unit,boost::units::scale<60,boost::units::static_rational<1,1>>>,boost::units::list<boost::units::metric::bar_base_unit,boost::units::dimensionless_type>>> 1> ] 1> c:\workspace\externals\boost_1_57_0\include\boost\units\unit.hpp(99) : see reference to class template instantiation 'boost::units::reduce_unit<S1>' being compiled 1> with 1> [ 1> S1=BSII::Units::bar_per_minute_unit 1> ] 1> c:\workspace\foundations\sw_foundations\bsii_common\test\src\units\units_pressure_test.cpp(97) : see reference to class template instantiation 'boost::units::is_implicitly_convertible<BSII::Units::bar_per_minute_unit,Unit>' being compiled 1> with 1> [ 1> Unit=BSII::Units::bar_per_minute_unit 1> ] According to the Boost documentation a homogeneous system can only be composed of linearly independent base units. In my case, I'm trying to mix bars (which in turn "contain" seconds as the time element) with minutes. This sounds problematic to me. But on the other hand, since I don't include mass and length base units in my system it seems to me that the base is independent after all. In any case, I searched online for an example of creating such a heterogeneous unit but didn't find anything comprehensible. Also, I read in the Boost documentation that a heterogeneous unit doesn't preserve information about how it was created. Does this mean I won't be able to, for instance, multiply BarPerMinuteRoC by Minute and get Bar back? Thanks a lot! Dina This message (including any attachments) is intended only for the use of the individual or entity to which it is addressed and may contain materials protected by copyright or information that is non-public, proprietary, privileged, confidential, and exempt from disclosure under applicable law or agreement. If you are not the intended recipient, you are hereby notified that any review use, dissemination, distribution, or duplication of this communication is strictly prohibited. If you are not the intended recipient, please contact the sender immediately by reply email and destroy all copies of the original. Thank you.

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[Preprocessor] Compile error after change from Boost 1.55 to 1.57
by Franz Alt 27 Feb '15

27 Feb '15

Hi, I've written some preprocessor directives to generate functions for a class. With Boost 1.55 everything works fine with gcc and clang. When I try to change to Boost 1.57 I've got some strange compile errors. I'm happy if someone could help. Thanks Franz gcc 4.9.1 failed with error: test.cpp:33:1: error: macro "BOOST_PP_SEQ_ELEM_III" requires 2 arguments, but only 1 given ) ^ test.cpp:33:1: error: macro "BOOST_PP_VARIADIC_ELEM_2" requires 4 arguments, but only 2 given test.cpp:60:1: error: macro "BOOST_PP_SEQ_ELEM_III" requires 2 arguments, but only 1 given MY_FUNCTION_BEGIN((b)) ^ test.cpp:60:1: error: macro "BOOST_PP_VARIADIC_ELEM_2" requires 4 arguments, but only 2 give clang 3.5.0 failed with error: test.cpp:30:3: error: too few arguments provided to function-like macro invocation MY_FUNCTIONS( \ ^ test.cpp:25:25: note: expanded from macro 'MY_FUNCTIONS' BOOST_PP_SEQ_FOR_EACH(FUNCTION_DECL, _, seq) ^ ..../boost.1_57_0/boost/preprocessor/seq/for_each.hpp:26:67: note: expanded from macro 'BOOST_PP_SEQ_FOR_EACH' # define BOOST_PP_SEQ_FOR_EACH(macro, data, seq) BOOST_PP_FOR((macro, data, seq (nil)), BOOST_PP_SEQ_FOR_EACH_P, BOOST_PP_SEQ_FOR_EACH_O, BOOST_PP_SEQ_FOR_EACH_M) ^ ..../boost.1_57_0/boost/preprocessor/repetition/detail/for.hpp:22:78: note: expanded from macro 'BOOST_PP_FOR_1' # define BOOST_PP_FOR_1(s, p, o, m) BOOST_PP_FOR_1_C(BOOST_PP_BOOL(p(2, s)), s, p, o, m) ^ note: (skipping 18 expansions in backtrace; use -fmacro-backtrace-limit=0 to see all) packages/boost/boost_i4/boost/preprocessor/seq/elem.hpp:22:39: note: expanded from macro 'BOOST_PP_SEQ_ELEM' # define BOOST_PP_SEQ_ELEM(i, seq) BOOST_PP_SEQ_ELEM_I(i, seq) ^ packages/boost/boost_i4/boost/preprocessor/seq/elem.hpp:41:45: note: expanded from macro 'BOOST_PP_SEQ_ELEM_I' # define BOOST_PP_SEQ_ELEM_I(i, seq) BOOST_PP_SEQ_ELEM_II(BOOST_PP_SEQ_ELEM_ ## i seq) ^ packages/boost/boost_i4/boost/preprocessor/seq/elem.hpp:43:62: note: expanded from macro 'BOOST_PP_SEQ_ELEM_II' # define BOOST_PP_SEQ_ELEM_II(im) BOOST_PP_SEQ_ELEM_III(im) ^ packages/boost/boost_i4/boost/preprocessor/seq/elem.hpp:44:13: note: macro 'BOOST_PP_SEQ_ELEM_III' defined here # define BOOST_PP_SEQ_ELEM_III(x, _) x The program is: #include <iostream> #ifndef BOOST_PP_VARIADICS #define BOOST_PP_VARIADICS #endif #include <boost/preprocessor.hpp> #define ADD_CONST_REF(op, data, elem) elem const & #define FUNCTION_DECL(r, data, tup) \ double BOOST_PP_TUPLE_ELEM(0, tup) \ BOOST_PP_IF(BOOST_PP_LIST_IS_NIL(BOOST_PP_TUPLE_TO_LIST(BOOST_PP_TUPLE_ELEM(1, tup))), \ (), \ BOOST_PP_SEQ_TO_TUPLE( \ BOOST_PP_SEQ_TRANSFORM( \ ADD_CONST_REF, \ _, \ BOOST_PP_TUPLE_TO_SEQ(BOOST_PP_LIST_TO_TUPLE(BOOST_PP_TUPLE_TO_LIST(BOOST_PP_TUPLE_ELEM(1, tup)))) \ ) \ ) \ ) \ const; #define MY_FUNCTIONS(seq) \ BOOST_PP_SEQ_FOR_EACH(FUNCTION_DECL, _, seq) class Foo { public: MY_FUNCTIONS( \ ((a, (int))) \ ((b) ) \ ) }; #define ADD_ARG(op, data, elem) elem const & BOOST_PP_CAT(a_, elem) #define MY_FUNCTION_BEGIN(tup) \ double Foo::BOOST_PP_TUPLE_ELEM(0, tup) \ BOOST_PP_IF(BOOST_PP_LIST_IS_NIL(BOOST_PP_TUPLE_TO_LIST(BOOST_PP_TUPLE_ELEM(1, tup))), \ (), \ BOOST_PP_SEQ_TO_TUPLE( \ BOOST_PP_SEQ_TRANSFORM( \ ADD_ARG, \ _, \ BOOST_PP_TUPLE_TO_SEQ(BOOST_PP_LIST_TO_TUPLE(BOOST_PP_TUPLE_TO_LIST(BOOST_PP_TUPLE_ELEM(1, tup)))) \ ) \ ) \ ) const \ { #define MY_FUNCTION_END() } MY_FUNCTION_BEGIN((a, (int))) { std::cout << "Foo::a(" << a_int << ")\n"; } MY_FUNCTION_END() MY_FUNCTION_BEGIN((b)) { std::cout << "Foo::b()\n"; } MY_FUNCTION_END() int main() { Foo f; f.a(42); f.b(); return 0; }

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VMD library accepted
by Steven Watanabe 27 Feb '15

27 Feb '15

AMDG The VMD library submitted by Edward Diener is ACCEPTED into Boost. I apologize for the long delay for this announcement. Thanks to everyone who participated in the formal review * Nial Douglass * Bjorn Reese * Rodrigo Madera * Zhou Zhenghui * Matt Calabrese * Paul Mensonides Reviews for the library were generally positive. The library was considered to be a useful set of tools for macro programmers. Paul expressed concern about the way the the library handles v-sequences and v-identifiers. After some discussion, Edward has agreed that the interface could be significantly improved. Work Items: * Add examples and improved motivation in the documentation * Update the v-identifier/v-sequence interface based on Paul's comments * Fix inaccurate statements about Boost.Preprocessor per Paul In Christ, Steven Watanabe

2 1

[Regex] Cannot build Regex without ICU
by Rob Desbois 26 Feb '15

26 Feb '15

I want to build the Boost libs without ICU support in Regex, but have been unable to prevent it from being linked in. I've run the following commands on a freshly extracted distribution of 1.57: ./bootstrap.sh --without-icu --prefix=/home/rob/workspace/deps/boost/1.57.0/linux/x64/ ./b2 install The bootstrap stage output includes this, which seems to indicate it's behaving correctly: Unicode/ICU support for Boost.Regex?... disabled. The resulting project-config.jam makes no mention of ICU. The build log includes: - has_icu builds : yes - icu : yes The shared library dependencies for the resulting libboost_regex.so.1.57.0 then include: libicuuc.so.50 => /lib64/libicuuc.so.50 (0x00007f74e5e3b000) libicui18n.so.50 => /lib64/libicui18n.so.50 (0x00007f74e5a3b000) libicudata.so.50 => /lib64/libicudata.so.50 (0x00007f74e4467000) I know the docs for Boost.Regex specify the bootstrap argument as --disable-icu, however this is rejected as invalid, unlike the argument I provide. Have I messed up somewhere or is this a bug? TIA -- rob -- Rob Desbois http://theotherbranch.wordpress.com/

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Re: [Boost-users] [ASIO] io_service::service::shutdown_service
by chmhou＠sina.com 25 Feb '15

25 Feb '15

>Hi, >Let us consider following execution sequence: >1. "io_service" destructor calls "io_service::service::shutdown_service"; >2. documentation of "io_service::service::shutdown_service" says that it >should destroy all user defined handler objects. >Is it true that user defined handler objects may access to (e.g. post a >handler) that "io_service" being destroyed and therefore has not exist >already? >Could You please also clarify me what does "user defined handler object" >really mean? >Thanks, >Andrew. Hi, Andrew For your 2nd question "user defined handler object", I supposed that the parameter for the io_service::post() which is kinda "user defined handler object". 1st, it could be a handler like "bind(&fun, this, _1, _2)". Martin

1 0

Why does read_xml call fail if my property tree contains char16_t?
by ashish g 24 Feb '15

24 Feb '15

Hi I have a property tree which has strings of char16_t as both key and value datatypes. When I try to call read_xml() to load an xml file into this tree it fails. The same code however works with wchar_t. Seems like its failing on parse_bom() function. The code and error message can be seen here: http://coliru.stacked-crooked.com/a/3f922b43838fd7e8 Any tips on how to fix this issue. -- *Ashish Gudla*

2 1

[fusion] Why is the std::tuple adapter undocumented?
by Rob Desbois 24 Feb '15

24 Feb '15

What it says on the tin really: Why is boost/fusion/adapted/std_tuple.hpp not documented at all? I'd like to use it but if it's undocumented because it's considered experimental then I'll use fusion's vector instead... TIA -- rob -- Rob Desbois http://theotherbranch.wordpress.com/

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Re: [Boost-users] Performance optimization in Boost using std::vector<>
by chmhou＠sina.com 24 Feb '15

24 Feb '15

Hi I got it, it supposed that I made a mistake on the duration. I will follow this question. Martin

1 0

Re: [Boost-users] Performance optimization in Boost using std::vector<>
by chmhou＠sina.com 23 Feb '15

23 Feb '15

>Hi, >not sure if the OP needs std::vector but... I'd recommend >boost::container::vector which has a dedicated constructor [1] and >resize() [2] method tagged with default_init_t argument, both of which >default initialize the values in the vector. For primitives it basically >means it leaves them uninitialized, hence there's no overhead when the >vector is to be filled with real data soon. >WBR, >Adam Romanek Hi Adam As following your point, the benefit of boost::container::vector supported the "default_init_t" method so that it 's quite convince and safety comparing with std::vector<> is that right ? are there additional advantages ? Hi Ilja You said "Boost::mpi version is always at least 10 times slower. " make me confused, I guess it's should be a typo, isn't ? Martin

3 2

Signals2 benchmark
by Joren Heit 22 Feb '15

22 Feb '15

Hi all, New to this list, so I hope I'm at the right place, and not asking too much of you guys. Please inform me if either of those is true! ;-) I have been working on a little toy project to implement a template-based Signal/Slot library and now that I have a usable end-product, I want to test it against boost::signals2 to get an idea of how well it performs. Therefore my first question is whether boost::signals2 is generally considered a high performance library. Second, I'm a little reluctant to build a benchmark suite myself, because I want to be fair to both myself and the other party. I don't know the signals2 library at all, let alone what its virtues and shortcomings are. Some tips on what to test exactly would therefore be great, although I'm afraid this request might qualify for "asking too much". Initial tests show that my own library can be up to 10 times faster than the boost-implementation, which makes me even more suspicious that I might not be testing the right things (but at the same time prematurely proud). Thanks in advance and cheers! Joren

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[ASIO] io_service::service::shutdown_service
by Andrew C 22 Feb '15

22 Feb '15

Hi, Let us consider following execution sequence: 1. "io_service" destructor calls "io_service::service::shutdown_service"; 2. documentation of "io_service::service::shutdown_service" says that it should destroy all user defined handler objects. Is it true that user defined handler objects may access to (e.g. post a handler) that "io_service" being destroyed and therefore has not exist already? Could You please also clarify me what does "user defined handler object" really mean? Thanks, Andrew.

1 0

Re: [Boost-users] Strange boost::threads behaviour
by Gavin Lambert 20 Feb '15

20 Feb '15

On 19/02/2015 21:11, Lorenzo Trivelli wrote: >> >> Typically the way things work is that as long as a lock (or >> whatever it is you're using -- you didn't actually say) goes >> uncontended, or minimally contended such that a spin resolves it, >> then it will allocate no kernel handles. A kernel handle is only >> required when the lock is contended for sufficiently long that it >> needs to put the thread to sleep. > > thank you ver much for your response, > I'll try to detail the issue better. > The original software is an conccurrent transactional server which > preallocates a certain number of ftherads (say 100 ~ 130) and then > accepts and serves TCP/IP connections in a request-reply fashion. While thread-per-connection is a popular model for older or small-scale software (because it's easy to program), performance suffers quite significantly when a large number of connections are in use, especially when each connection needs to contend on the same locks. Especially if the workload is mostly I/O bound rather than CPU bound, you may want to consider a "properly" async design (eg. using Boost.Asio) where #threads == #cores (or thereabouts) and connection processing can shift between threads as needed. > Obviuosly, it heavily uses boost::shared_ptr to handle these connections, > but in the end I managed to use other shared pointers (for testing purposes only) > and the boost::thread object alone and a single shared static mutex object > > so, the sample program starrts, creates some threads which simply does some memory > allocations loops and s. In the main function I enclosed all the code between brackets, > and I print the handle count before and after, ans it's not the same, > something like > int main() { > GetProcessHandleCount().... > > { > [creates threads and waits for their termination through ->join] > > } > GetProcessHandleCount().... > > } > > The difference between the first and the last count is not always the same, it > depends on how much concccurent threads you create and how much iterations of the > same loop each thread does. Well, as I said that is not an error if some synchronization objects (eg. mutexes) still exist.

1 0

"xtime" ambiguous symbol in MSVC 12
by Kevin Williams 19 Feb '15

19 Feb '15

Hi I get a C2872 when including "chrono" (allegedly line 738) from MSVC 12, and also needing boost::mutex. I believe the boost mutex is a bit faster than std::mutex, and I need that. Many thanks, Kevin

2 1

Re: [Boost-users] Strange boost::threads behaviour
by Gavin Lambert 19 Feb '15

19 Feb '15

On 17/02/2015 04:01, Lorenzo Trivelli wrote: > While analyzing a resource exaustion problem on a production machine, > (Windows) I found out astrange behaviour of boost::threads regarding event object. > The problem is that after a certain number of iterations it semms that the > thread lib allocates an EventHandle which is never freed. > I managed to reproduce in some ways the behaviour, but I'm a bit clueless > about its reason. Typically the way things work is that as long as a lock (or whatever it is you're using -- you didn't actually say) goes uncontended, or minimally contended such that a spin resolves it, then it will allocate no kernel handles. A kernel handle is only required when the lock is contended for sufficiently long that it needs to put the thread to sleep. This handle should be released when the lock itself is deleted. If the lock is itself global or otherwise held by a global object, or if it's in an object that you are memory-leaking, then it won't go away until you close the process. > 3) if you want I can attach the sample code with a but if info > on how to reproduce the behaviour Without knowing at least *which* threading object you're using, I doubt a report will get anywhere.

2 1

Need help to build ( cross compile) Boost for ARM
by som jagadeeshan 18 Feb '15

18 Feb '15

Hello All, Currently I’m trying to get the boost_1_57_0 library built for ARM. But i don’t find any help on how to go about this. I'm using the poky hard float tool chain to get the library cross compiled(*arm-poky-linux-gnueabi-*) Any help on how to get this will be great. The below log is what i get when running the script file ( bootstrap.sh) $ ./bootstrap.sh *Building Boost.Build engine with toolset gcc... Failed to build Boost.Build build engineConsult 'bootstrap.log' for more details* Thanks, Mike

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Boost MultiIndexContainer, how to do delayed indexing for fast insertion?
by HuMichael 17 Feb '15

17 Feb '15

I used below MultiIndexContainer typedef multi_index_container<PositionSummary*, indexed_by< ordered_unique< composite_key<PositionSummary, const_mem_fun<PositionSummary, int, &PositionSummary::positiondate>, const_mem_fun<PositionSummary, const std::string&, &PositionSummary::accountid>, const_mem_fun<PositionSummary, const std::string&, &PositionSummary::instid> > >, ordered_unique< composite_key<PositionSummary, const_mem_fun<PositionSummary, int, &PositionSummary::positiondate>, const_mem_fun<PositionSummary, const std::string&, &PositionSummary::instid>, const_mem_fun<PositionSummary, const std::string&, &PositionSummary::accountid> > > > > PositionSummaryContainer; And I inserted 10000 insts*36 accounts*100 days=36 million records //Begin testing of the multiIndexContainter std::cout << "Begin inserting data from array into the multiIndexContainter" << std::endl; timer.reset(); timer.begin(); for (int i = 0; i < numOfDays_; i++) { for (int j = 0; j < accountSize_; j++) { for (int k = 0; k < instSize_; k++) { PositionSummary* ps = psArray_[(i * accountSize_ + j) * instSize_ + k]; uniqueIndex.insert(ps); } } } printMemoryUsage(); timer.end(); std::cout << "Time take is " << timer.getInterval() << std::endl; And I found the speed of insertion is a little bit slow, about 20K+ records per second... Is there anyway to enhance this insertion speed? My data was in Oracle, properly indexed, so there should be no danger of corrupted data structure. I knew that in oracle you can first load then build index to save time, can I do the same with MultiIndexContainer, if there is a way? By the way, the parallel query speed is quite satisfactory, querying all the 36 m records on a 4 cpu(8kernal) machine takes only 2.8 seconds, code as below #pragma omp parallel for collapse(2) for (int i = 0; i < numOfDays_; i++) { for (int j = 0; j < accountSize_; j++) { const int& date = dates_[i]; const std::string& accountID = accountIDs_[j]; for (int k = 0; k < instSize_; k++) { const std::string& instID = instIDs_[i]; PositionSummaryContainer::iterator it = uniqueIndex.find(boost::make_tuple(date, accountID, instID)); if (it != uniqueIndex.end()) { #pragma omp atomic sum2 += (*it)->marketvalue(); } } //std::cout << "accountID: " << accountID << std::endl; } }

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[gsoc15] Org application closes on Friday 20th
by Niall Douglas 17 Feb '15

17 Feb '15

Three days remain until the GSoC org application closes on Friday 20th of April. As can be seen at https://svn.boost.org/trac/boost/wiki/SoC2015, we have just SIX project proposals and FIVE mentors who have publicly made themselves available on the ideas list this year. This is significantly lower than this time last year. If you would like to attract students to work on your Boost library in 2015, please consider adding a formal project idea to the list above before Friday. If you would like to mentor in some topic or field, please make yourself known to us so we can add you to the list of available mentors for 2015. Oh, and don't forget to mention the fields you are interested in! Thanks, Niall and Boris --- Boost C++ Libraries Google Summer of Code 2015 admin https://svn.boost.org/trac/boost/wiki/SoC2015

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generic vector
by U.Mutlu 17 Feb '15

17 Feb '15

Hi, I need to have a std::vector in my program, but it's type will be known only when it runs, ie. the type will be provided via a program param. The possible types are limited to these: int64_t, uint64_t, double, std::string. Is there a solution in boost or C++11 for this kind of problem? -- TIA Uenal

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[regex] problem w/ regex::extended
by U.Mutlu 16 Feb '15

16 Feb '15

Hi, the following regex expression works in perl-mode, but does not work in extented-mode. What's the reason? I think I haven't used any perl-specific construct, or did I? Where? ... #define NUM "[+-]?(\\d+\\.?\\d*|\\.\\d+)([eE][+-]?\\d+)?" #define WORD "[\\w\\-\\.~/]+" #define EQU "\\s*\\=\\s*" const string sUserRE_VarAndVal = WORD EQU NUM; #if 0 #define REGEX_ENGINE boost::regex::extended #else #define REGEX_ENGINE boost::regex::perl #endif regex reNum(sUserRE_VarAndVal, REGEX_ENGINE); ...

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[program options] option_groups.cpp example doesn't compile
by U.Mutlu 16 Feb '15

16 Feb '15

I've boost 1.55 from the debian repository. I'm trying to compile the below example of the 1.55 version (it's same as that of 1.57), but I get the following compile errors. Should I use some 'magic' compiler options, or what else is the reason for this grandious failure? $ g++ -Wall -std=gnu++11 option_groups.cpp -lboost_program_options option_groups.cpp: In function ‘int main(int, char**)’: option_groups.cpp:44:46: error: ‘class boost::program_options::typed_value<std::basic_string<char>, char>’ has no member named ‘implicit’ ("help-module", value<string>()->implicit(), ^ option_groups.cpp:96:11: error: reference to ‘exception’ is ambiguous catch(exception& e) { ^ In file included from /usr/include/c++/4.9/new:40:0, from /usr/include/c++/4.9/ext/new_allocator.h:33, from /usr/include/x86_64-linux-gnu/c++/4.9/bits/c++allocator.h:33, from /usr/include/c++/4.9/bits/allocator.h:46, from /usr/include/c++/4.9/string:41, from /usr/include/boost/program_options/errors.hpp:12, from /usr/include/boost/program_options/options_description.hpp:12, from option_groups.cpp:24: /usr/include/c++/4.9/exception:60:9: note: candidates are: class std::exception class exception ^ In file included from /usr/include/boost/throw_exception.hpp:43:0, from /usr/include/boost/any.hpp:26, from /usr/include/boost/program_options/value_semantic.hpp:12, from /usr/include/boost/program_options/options_description.hpp:13, from option_groups.cpp:24: /usr/include/boost/exception/exception.hpp:208:5: note: class boost::exception exception ^ option_groups.cpp:96:11: error: ‘exception’ does not name a type catch(exception& e) { ^ option_groups.cpp:97:17: error: ‘e’ was not declared in this scope cout << e.what() << "\n"; ^

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[context] boost::coroutines::asymmetric_coroutine<T>::pull_type iterator does not properly model InputIterator
by Mueller-Roemer, Johannes Sebastian 16 Feb '15

16 Feb '15

I’m currently on Boost 1.56 so this might have been fixed by now, but in a simple test Boost.Coroutine fails to properly model the InputIterator concept, because *it++ does not conform to the operational semantics { T tmp = *it; ++it; return tmp; } required by the standard. The failing program: #include <boost/coroutine/asymmetric_coroutine.hpp> #include <iostream> template<typename Continuation> auto foo(Continuation && yield) -> void { yield("Hello"); yield(", "); yield("World"); yield("!\n"); } //using T = char const *; using T = std::string; auto foo() -> boost::coroutines::asymmetric_coroutine<T>::pull_type { using namespace boost::coroutines; return asymmetric_coroutine<T>::pull_type{ [](asymmetric_coroutine<T>::push_type& yield) { foo(yield); } }; } auto main(int, char **) -> int { auto f = foo(); for(auto it = boost::begin(f); it != boost::end(f);) std::cout << *it++; } Which (on my machine) outputs: , World! X☺à r2 ` , ` , Ç2 Ç Failing to model the InputIterator concept is bad, because then it isn’t any kind of standards-conforming iterator at all. Interestingly, if T is char const * and not std::string the program works as expected. Is there some other subtle bug at work here? -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer(a)igd.fraunhofer.de | www.igd.fraunhofer.de

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Strange boost::threads behaviour
by Lorenzo Trivelli 16 Feb '15

16 Feb '15

Hi to everyone, first of all thanks to all the people who writes and manteins this wondefrul collection of libraries ;-) While analyzing a resource exaustion problem on a production machine, (Windows) I found out astrange behaviour of boost::threads regarding event object. The problem is that after a certain number of iterations it semms that the thread lib allocates an EventHandle which is never freed. I managed to reproduce in some ways the behaviour, but I'm a bit clueless about its reason. To be honest, the amount of handles "leaked" by the test code is quite less than the amount I found on production server, but test code is also quite simpler. Now some info: 1) OS: Win 2033 , Win 2008 2) I tested it with both 1.46.1 and 1.57.0, compiled using stlport using VS2005 3) if you want I can attach the sample code with a but if info on how to reproduce the behaviour thanks in advance L. Trivelli

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[future] Confused about the represents in Doc "boost::future"
by Cheng Mo 16 Feb '15

16 Feb '15

Hi all : I got confused in Doc of boost :: futures and I can't got the point of sort of terms. The represents in Overvies of Futures like " Instances can be freely copied and assigned, and boost::shared_future<R>::get() returns a non const reference so that multiple calls to boost::shared_future<R>::get() are safe." no doubt that a const reference .... are safe. a non const reference could be changed by external stimuli. isn't ? Or the key is "Instances can be freely copied" , so that we can say "are safe"? Cheer~ Martin

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[program options] examples where?
by U.Mutlu 15 Feb '15

15 Feb '15

In the online documentation tutorial there are multiple times mentioned references to the examples page. But where are these examples exactly located? On the documentation pages I couldn't find a link to the examples page. Do I need to install the complete boost developer version locally to get to the examples? -- cu Uenal

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[program options] an alternative for "add_options()" avail?
by U.Mutlu 15 Feb '15

15 Feb '15

Hi, I'm newbie to 'program options'. I just wanted to ask if there is an alternative for the below example from the online-doc: desc.add_options() ("help", "produce help message") ("compression", po::value<int>(), "set compression level") ; I would like to have something more traditional like the following single element addition alternative: desc.add_option("help", "produce help message"); desc.add_option("compression", po::value<int>(), "set compression level"); Is something like this already in the library? -- TIA Uenal

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